package com.leetcode.no64;

import java.math.*;

class Solution {
    public int minPathSum(int[][] grid) {
        int m = grid.length;
        int n = grid[0].length;

        if (m <= 0 || n <= 0) {
            return 0;
        }

        int[][] dp = new int[m][n];

        dp[0][0] = grid[0][0];

        // 第一行
        for (int i = 1; i <= n - 1; i++) {
            dp[0][i] = dp[0][i - 1] + grid[0][i];
        }

        // 第一列
        for (int i = 1; i <= m - 1; i++){
            dp[i][0] = dp[i-1][0] + grid[i][0];
        }

        for(int i =1; i<=m-1; i++){
            for(int j=1; j<=n-1; j++){
                dp[i][j] = Math.min(dp[i-1][j], dp[i][j-1]) + grid[i][j];
            }
        }
        return dp[m-1][n-1];
    }
}